SPEED OPTIMIZED TRAJECTORY CONTROL FOR MOTOR VEHICLES

• US 20160229452A1
• Filed: 02/10/2015
• Published: 08/11/2016
• Est. Priority Date: 02/10/2015
• Status: Active Application

• Current Assignee: Ford Global Technologies, LLC (Ford Motor Company)
• Original Assignee: Ford Global Technologies, LLC (Ford Motor Company)
• Inventors: Rolfes, Nathaniel A., Lavoie, Erick Michael, Hochrein, Bradley G., Recker, Darrel Alan, Mattern, Donald Jacob, Hafner, Michael
• Granted Patent: US 10,286,950 B2
• Time in Patent Office: Days
• US Class Current: 1/1
• CPC Class Codes: B60W 10/04 including control of propulsion units
• CPC Class Codes: B60W 10/18 including control of braking systems
• CPC Class Codes: B60W 2300/14 Tractor-trailers, i.e. combinations of a towing vehicle and one or more towed vehicles, e.g. caravans; Road trains
• CPC Class Codes: B60W 2520/22 Articulation angle, e.g. between tractor and trailer
• CPC Class Codes: B60W 2540/18 Steering angle
• CPC Class Codes: B60W 2720/10 Longitudinal speed
• CPC Class Codes: B60W 30/146 Speed limiting
• CPC Class Codes: B60W 30/18036 Reversing
• CPC Class Codes: B62D 13/06 for backing a normally drawn trailer
• CPC Class Codes: B62D 15/027 Parking aids, e.g. instruction means

Abstract

A trailer backup assist system for motor vehicles includes an auxiliary user input feature that can be used by a vehicle operator to provide a steering curvature command corresponding to a desired vehicle path curvature without requiring a user to move a steering wheel of the motor vehicle. The trailer backup assist system is configured to control a vehicle speed while the vehicle is backing up with a trailer attached thereto utilizing an input comprising at least one of a steering curvature command and an angle of a trailer relative to the vehicle. The trailer backup assist system controls at least one of a brake system, an engine torque, and a transmission gear selection to thereby control vehicle speed in a reverse direction.

Claims

1. A trailer backup assist system for motor vehicles, the trailer backup assist system comprising:

an auxiliary input feature in a vehicle interior that can be used by a vehicle operator to provide a steering request corresponding to a desired vehicle path without requiring a user to move a steering wheel;

wherein the trailer backup assist system is configured to control a vehicle speed while the vehicle is backing up with a trailer attached thereto utilizing an input comprising at least one of a steering request and an angle of a trailer relative to the vehicle, and wherein the trailer backup assist system generates a command to control at least one of a brake system, an engine torque, and a transmission gear selection to thereby control vehicle speed in a reverse direction.

2. The trailer backup assist system of claim 1, wherein:

the brake system comprises a vehicle brake system.

3. The trailer backup assist system of claim 1, wherein:

the trailer backup assist system limits vehicle speed in a reverse direction as a function of a trailer angle.

4. The trailer backup assist system of claim 1, wherein:

the trailer backup assist system limits vehicle speed in a reverse direction as a function of a steering request by a user.

5. The trailer backup assist system of claim 1, wherein:

the trailer backup assist system determines at least one maximum allowable speed in reverse based on at least one of a trailer angle and a steering request of a user.

6. The trailer backup assist system of claim 5, wherein:

the trailer backup assist system utilizes a predefined relationship to determine a maximum allowable speed based on at least one of a trailer angle and a steering request of a user.

7. The trailer backup assist system of claim 6, wherein:

the maximum allowable speed varies linearly as a function of at least one of a trailer angle and a steering request of a user.

8. The trailer backup assist system of claim 1, including:

a brake system control module;

a powertrain system control module;

a hitch angle detection apparatus; and

wherein the trailer backup assist system obtains a trailer angle from the hitch angle detection apparatus and generates a command to at least one of the brake system control module and the powertrain system control module to limit a maximum vehicle speed in a reverse direction.

9. The trailer backup assist system of claim 1, wherein:

the auxiliary user input feature comprises a rotatable knob.

10. A method of controlling a reverse speed of a motor vehicle and trailer comprising;

utilizing a steering request from an auxiliary user input feature positioned in a vehicle interior as an input;

determining a desired vehicle and trailer path utilizing the input;

determining an acceptable error criteria relative to the desired vehicle and trailer path;

controlling vehicle speed to move the vehicle within the acceptable error criteria in a reverse direction utilizing the input.

11. The method of claim 10, including:

utilizing at least one of a vehicle brake system and a trailer brake system to limit vehicle speed in a reverse direction.

12. The method of claim 10, including:

controlling a vehicle transmission to limit vehicle speed.

13. The method of claim 10, including:

determining a maximum allowable vehicle speed in a reverse direction as a function of at least one of a trailer angle and an input comprising a steering curvature command;

controlling at least one of a braking system, an engine torque, and a transmission gear selection to prevent the motor vehicle from exceeding the maximum allowable vehicle speed.

14. The method of claim 13, including;

measuring a trailer angle; and

wherein;

the maximum allowable vehicle speed is a linear function of the trailer angle.

15. The method of claim 13, including:

determining a maximum allowable vehicle speed in a reverse direction as a function of both a trailer angle and an input comprising a steering curvature command.

16. A method of controlling a speed of a motor vehicle and trailer, comprising:

determining a desired vehicle and trailer path utilizing input from an input feature inside the vehicle;

determining an acceptable error criteria relative to the desired vehicle path;

limiting a speed of a vehicle by controlling at least one of a vehicle brake, an engine torque, and transmission such that the vehicle moves along the desired vehicle path within the acceptable error criteria.

17. The method of claim 16, wherein:

the vehicle includes an active park assist system that can be actuated by an operator such that the active park assist system controls at least one of a vehicle steering system and a vehicle speed in a reverse direction during parking operations; and

including;

utilizing a steering command that is generated by the vehicle'"'"'s active park assist system as an input to control a speed of a vehicle.

18. The method of claim 16, wherein:

the vehicle includes a power steering system that changes a steering angle of one or more wheels of the vehicle, and wherein the power steering system defines a maximum angular velocity at which the steering angle can change, and wherein the power steering system defines a time lag between the time at which the power steering system receives a steering command and the time at which the steering angle of the one or more wheels of the vehicle reaches an angle corresponding to the steering command; and

including;

limiting a speed of the vehicle to account for at least one of the maximum angular velocity and the time lag.

19. The method of claim 18, wherein:

the vehicle includes a trailer backup assist system whereby the input feature can be used by a vehicle operator when the trailer backup assist system is active to provide an input comprising a user steering request; and

including;

utilizing the user steering request from the input feature to determine the desired vehicle path when the vehicle is backing up.

20. The method of claim 16, including:

controlling a path of a vehicle to avoid a collision; and

generating a warning to a vehicle operator that a collision mitigation function is active.